RESUMEN
BACKGROUND: The objective of this study was to assess the immunogenicity and reactogenicity of the combined adsorbed tetanus toxoid, low dose diphtheria toxoid, 5-component acellular pertussis and inactivated polio vaccine (TdcP-IPV) as compared with a pediatric dose diphtheria formulation, combined with adsorbed tetanus toxoid and 3-component acellular pertussis (DTacP), in 6-year-old children who were immunized with 4 doses of diphtheria-tetanus-whole cell cellular pertussis (DTwcP) plus oral polio vaccine (OPV) before 2 years of age, according to the local Spanish vaccination calendar. METHODS: One hundred ninety-four healthy 6-year-old children were randomized to receive 1 dose of TdcP-IPV or 1 dose of DTacP and OPV. RESULTS: One month postvaccination, antidiphtheria and antitetanus titers were > or =0.1 IU/mL in 100% of patients in both study groups. TdcP-IPV reached 100% seroprotection rates against polio types 1, 2 and 3. In OPV recipients, these rates were 100, 100 and 96.8%, respectively. Seropositivity rates for pertussis toxin, filamentous hemagglutinin, pertactin and fimbrial components of the TdcP-IPV vaccine were 97.9, 89.6, 90.6 and 100%. The incidence of local and systemic reactions was 50.5 and 39.2% in the TdcP-IPV group and 59.4 and 38.5% in the DTacP plus OPV group, and no serious adverse events were reported. CONCLUSIONS: TdcP-IPV vaccine was shown to be immunogenic and safe when given as a booster in children 6 years of age who were primed with 4 doses of DTwcP and OPV.
Asunto(s)
Vacuna contra Difteria, Tétanos y Tos Ferina/inmunología , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/inmunología , Inmunidad/fisiología , Vacuna Antipolio Oral/inmunología , Niño , Vacuna contra Difteria, Tétanos y Tos Ferina/administración & dosificación , Vacunas contra Difteria, Tétanos y Tos Ferina Acelular/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Esquemas de Inmunización , Memoria Inmunológica , Masculino , Vacuna Antipolio Oral/administración & dosificación , Medición de Riesgo , Sensibilidad y Especificidad , Método Simple Ciego , Vacunas Combinadas/administración & dosificación , Vacunas Combinadas/inmunologíaRESUMEN
PURPOSE: To determine the incidence of pertussis in persons < or =15 years in age in Valencia, Spain. To assess the prevalence of IgG antibodies to pertussis toxin (PT) in children, adolescents and adults. METHODS: Prospective study conducted at paediatric primary care centres. All persons < or =15 years in age presented with persistent cough were enrolled. Parents completed a brief questionnaire and immunization history was obtained from paediatrician records. A blood sample was obtained, for determination of IgG antibodies to Bordetella pertussis toxin (PT) by an ELISA method. A study confirmed-case was the presence of two conditions: (1) cough illness of > or =14 days duration; and (2) ELISA absorbance value of IgG to PT > or =2. Two subjects per clinical-case (same centre and range of age) and parents were asked to participate in the prevalence study. RESULTS: Sixty-one children < or =15 years in age presented with symptoms leading to a clinical diagnosis of pertussis were detected. Serological evidence of recent pertussis was found in five of these patients (incidence of 46.0/100,000 persons < or =15 years in age). Prevalence of antibodies to B. pertussis (> or =0.3) in children < or =15 years in age and adults was 39 and 33%, respectively. Only a minority of children, adolescents and adults had absorbance values indicative of immunity (> or =1). CONCLUSIONS: These incidence and seroprevalence results show that despite high immunization rates in infancy, B. pertussis is circulating in Spain.